
This application is based on Patent Application No. 2001-062476 filed Mar. 6, 2001 in Japan, the content of which is incorporated hereinto by reference.
1. Field of the Invention
The present invention relates to a card connector which can be mounted on electronic devices, such as cellular phones, telephones, PDAs (personal digital assistants), portable audio devices, cameras and the like, and more particularly to a compact card connector capable of reliably locking an IC card therein.
2. Related Background Art
Known IC cards have memory and/or an IC for serving as a control circuit. By loading such an IC card into electronic apparatuses such as cellular phones, telephones, PDAs, cameras and the like, functions of these electronic apparatuses can be enhanced. Examples of such IC cards include memory cards such as Subscriber Identity Module Card (SIM card), Multi Media Card (MMC), Smart Media, Secure Digital Card (SD card), Memory Stick, and Compact Flash Card.
A card connector is built into the electronic apparatus so as to allow above IC cards to removably connect with the electronic apparatus. The card connector generally has a connector body including a card slot and a plurality of metal contact terminals. Each of contact terminals of the card connector comes to contact with a corresponding contact pad arranged on a front surface or a rear surface of the IC card when the IC card is inserted in the card slot. A contact between contact terminals of the card connector and contact pads of the IC card allows electrical connection between the electric apparatus and the IC card. That is, the contact pads of the IC card include power-source pads to be connected to a power source and a plurality of signal pads for transmitting and receiving various signals. These contact pads are respectively connected to a power source circuit or various signal processing circuits of the electronic apparatus with a plurality of contact terminals of the card connector.
Many of the card connectors mounted on these electronic devices include an eject mechanism to eject an inserted card therefrom. The conventional eject mechanisms are available in the following types.
In one type of the conventional eject mechanism, an insertion length of the card into a card slot is so determined that the rear end of the card protrudes from the card slot. When ejecting the card from the card slot, users can be held the rear end of the card with their fingers to pull out the card from the card slot.
The other type of the conventional eject mechanism includes an eject button provided near the card slot. When ejecting the card from the card slot, a user presses the eject button. By pressing the eject button, the eject mechanism is operated to eject the card from the card slot.
In the former type, however, the rear end of the card protruding from the card slot spoils the appearance of the card connector or the electronic apparatus. Moreover, this increases a chance of the card being damaged by external impacts and requires force to pull out the card from the card slot. The latter type, on the other hand, has difficulty in arranging the eject button at an appropriate position due to a space limitation and also has problems of the eject button spoiling the appearance of the card connector and hindering a size reduction.
To solve these problems, an eject mechanism of Japanese Patent Application Laid-open No. 2000-251025 has been proposed. FIG. 14 is an exploded view of the proposed mechanism. The conventional eject mechanism of FIG. 14 is so-called Push-Push (Push-in/Push-out) type card eject mechanism including a generally heart-shaped cam element 105, a cam lever 108, and the like. This eject mechanism operates to eject the card from the card slot when the inserted card is further pushed into the card slot.
As shown in FIG. 14, the conventional eject mechanism further includes an eject member 100 with a triangular projection 101 and a coil spring 103 disposed between a lower plate 102 and the eject member 100. The lower plate 102 constitutes a connector body and defines a card slot. A guide way 104 is formed on the lower plate 102 to guide the sliding movement of the eject member 100. The cam element 105 is formed on the lower plate 102. Around the cam element 105, lever guide ways 107a and 107b are formed to guide the movement of the cam lever 108. The cam lever 108 has a first end secured to the eject member 100 and a second end 108a capable of moving along the lever guide ways 107a and 107b. 
When a card is inserted in the card slot defined by the lower plate 102, an cut-off corner portion of the card (not shown) abuts against the triangular projection 101 of the eject member 100. The eject member 100 is pushed by the card and is thus moved against the force of the coil spring 103 toward the interior of the card slot. At this time, the second end 108a of the cam lever 108 moves along the lever guide way 107a until it is engaged with a depressed locking surface 105a of the cam element 105. Now, the card is held immovable in the card slot with the contact pads of the card being in contact with the contact terminals of the connector.
When ejecting the card from the card slot, the user slightly pushes the inserted card inward. This disengages the cam lever 108 (second end 108a) from the locking portion 105a of the cam element 105. Then, the second end 108a of the cam lever 108 is moved along the lever guide way 107b by the restoring force of the coil spring 103. The eject member 100 therefore moves to eject the card by the card abutment portion 101 thereof.
In a card connector provided with the above described push-push type eject mechanism, an eject operation may cause a card to rush out from the card slot and to fall out of the connector (card slot). To prevent the card from falling out in this manner or falling out due to unexpected external force exerted when the card is inserted, an elastic brake (stopper) may be provided in a connector body at a predetermined location. This brake means may apply frictional force to the card in the card slot in the direction opposite to that in which the card may fall out (card eject direction).
However, it will be appreciated that the friction between the brake means and the card is not increased beyond a required level in order to allow the card to be easily removed from the connector. Accordingly, it may be difficult to reliably prevent the card from falling out of the card slot by a mechanism which includes only the brake means. Thus, the conventional card connectors still fail to prevent the card from falling out of the card slot.
On the other hand, there has been a strong demand for a decrease in the size, height, and weight of the card connector. Accordingly, the mechanism for preventing the card from falling out must be smaller and lighter.
It is an object of the present invention to solve the above described problems. The present invention provides a card connector which can reliably lock an inserted card and which can maintain the locked state even if an attempt is made to forcibly remove the card.
One aspect of the present invention relates to a card connector which can accommodate an IC card having a locking depressed portion formed in one side thereof and a plurality of contact pads arranged on a bottom surface thereof. The connector according to the present invention comprises a connector body, an eject member, a cam lever, a press member, an elastic locking piece, a locking piece displacing member, and an opening formed in the connector body.
The connector body includes a card slot for accommodating the IC card and a plurality of contact terminals adapted to respectively contact with the corresponding contact pad of the IC card. The eject member can move in a card insert direction relative to the connector body in response to an insertion of the IC card. The eject member can also move in a card eject direction relative to the connector body in response to a predetermined card eject operation to eject the IC card from the card slot. The eject member includes a generally heart-shaped cam element. One end of the cam lever is supported by the connector body, while another end of the cam lever is allowed to move along a cam profile of the cam element.
The press member is disposed inside the connector body. The press member is supported by the connector body in a cantilever manner and elastically presses the cam lever so that the another end of the cam lever maintains to contact with the cam profile of the cam element. The elastic locking piece is fixed to the eject member and has an engaging portion capable of engaging with the locking depressed portion of the IC card. Upon card insertion and ejection, the elastic locking piece cooperates with the locking piece displacing member. That is, when the eject member moves in the card eject direction, the elastic locking piece is displaced by the locking piece displacing member so that the engaging portion thereof is disengaged from the locking depressed portion of the card. Further, when the eject member moves in the card insert direction, the elastic locking piece is displaced by the locking piece displacing member so that the engaging portion thereof engages with the locking depressed portion.
If a user pulls the card to remove it from the card slot when the elastic locking piece engages with the locking depressed portion to lock the IC card in the connector body, the elastic locking piece is also pulled together with the IC card. Since the elastic locking piece is fixed to the eject member, it pulls the eject member in a direction in which the card is pulled. In this situation, the movement of the eject member is basically regulated by cam lever and the heart-shaped cam element engaging each other and the press member which elastically presses the cam lever against the cam element.
However, under this condition, if the user forcibly pull the card to remove it from the card slot, the cam lever may be disengaged from the cam element against the pressing force of the press member. In such a case, the card may be easily pulled out and in some cases, the eject mechanism may be broken.
Thus, the card connector of the present invention comprises the opening. The opening is appropriately sized to expose only a part of the press member to an outside of the connector body so that a distal end of the press member contacts with the connector body. That is, the opening allows the press member to be elastically displaced with regulating the movement of the distal end of the press member. As a result, if the cam lever likely disengages from the cam element against the pressing force of the press member, the movement of the cam lever is regulated by the connector body having enough strength. Therefore, even if the user inadvertently attempts to forcibly remove the card, the card cannot be easily removed, and the eject mechanism is reliably prevented from being broken.
In another aspect of the present invention, the generally heart-shaped cam element is formed in the connector body. Further, one end of the cam lever is supported by the eject member, while the other end the cam lever is allowed to move along the cam profile of the cam element.
The above and other objects, effects, features and advantages of the present invention will become more apparent from the following description of embodiments thereof taken in conjunction with the accompanying drawings.